I used to consider myself a photographer, and on occasion I teach pinhole
photography. I'll begin another pinhole photography unit in a couple of
weeks. I always start with the physics of light, because without light we
would not have photography, or even vision. What we see actually isn't the
world, but light reflected off of the world. To understand this it is
important to learn that light travels in straight rays from the light
source, to the object, then bounces off the object into our light receptors
(eye lens or camera lens). The eye and camera lenses both have the same
purpose, which is to organize the light rays that are bouncing around in all
directions all the time. The eye or camera lens eliminates extraneous light
so only the light reflecting off the subject reaches the retina or film. The
teach this concept my classes make a camera obscura similar to the ones that
Vermeer used. Sometimes we make the camera obscura out of a refrigerator
box, but this time I plan on blacking out the whole room, and putting a
small hole in the window covering. The light is going to come from the sun,
bounce in straight rays off of the playground, marsh and hills behind the
school, right through the hole (+- 1/4" diameter) and land (upside down and
backwards) on the big white wall on the opposite side of the room. Then we
can trace the image on a big paper taped to the wall, but not before we take
turns dancing around outside the window so the others inside can watch. For
your 15 or 20 minutes maybe you could set up a camera obscura beforehand and
let them experience that. I hope I've given you some ideas and answered your
questions. Be sure to let me know if you need more information.
Peace, Mark

----- Original Message -----
From: "Tiffany M Wyse" <tiffanymw@goshen.edu>
> Hello, I need to teach a fifteen to twenty minute lesson on how
> photographers use lighting and why lighting and shadows are important in
photography. Help! Does anyone have any ideas?